Cooling tunnel

ABSTRACT

A cooling tunnel having an L-shaped cross-section defining a horizontal leg and a vertical leg. The material-receiving run of a continuous conveyor passes through the horizontal leg, and the reverse conveyor run is located outside the tunnel. An evaporator is arranged within the vertical leg, and a guide sheet extends from the evaporator into the horizontal leg dividing the latter into upper and lower cooling zones. A ventilator directs air downwardly through the evaporator and through the cooling zones in directions perpendicular to the direction of movement of the conveyor. The lower end of the vertical leg is formed to collect condensation and is provided with an outlet for removing condensed water.

United States Patent [191 Sollich 1 Oct. 30, 1973 COOLING TUNNEL 21Appl. No.: 209,807

[30] Foreign Application Priority Data Mar. 27, 1971 Germany P 21 14906.4

[52] US. Cl 165/120, 62/63, 62/378 2,307,562 l/l943 Bausman 621380 XPrimary ExaminerCharles J. Myhre Att0meyAlan H. Levine [57] ABSTRACT Acooling tunnel having an L-shaped cross-section defining a horizontalleg and a vertical leg. The materialreceiving run of a continuousconveyor passes through the horizontal leg, and the reverse conveyor runis located outside the tunnel. An evaporator is arranged within thevertical leg, and a guide sheet extends from 51 Int. Cl F24h 3/02 theevaporator into the horizontal leg dividing the [58] Field of Search 0.62/63, 378, 380; Ier into upper and lewer eeeling lenes- A ventilator165/120 directs air downwardly through the evaporator and a through thecooling zones in directions perpendicular [56] References Cited to thedirection of movement of the conveyor. The

UNITED STATES PATENTS lower end of the vertical leg is formed to collectcon- 2 483 605 10/1949 Ab 63/378 x densation and is provided with anoutlet for removing ramson d d t 2,974,497 3/1961 Carpenter et al 62/63con ense wa er 3,472,043 10/1969 Nelson 165/120 X 7 Claims, 1 DrawingFigure l l I \\\g Q s@\\ t 12 135 4. 1 mm W is 3 K 7 3 7+ 1 7 v21. 5?\i\ :t\t\\ :\\;/i :\\b i \\\\\.I \l- T if 1i 10 3b 2 i 1:: 5; i i 9 3g}.

COOLING TUNNEL The invention relates to a cooling tunnel having acontinuous conveyor belt for the material to be cooled, which tunnel isintended to be preferably employed as a member of a working train in thepraline or biscuit industries.

For example, it is the general practice with the production ofchocolate-coated biscuits to continuously feed the biscuits, passing outof a band oven, to a coater, in which the biscuits are totally orpartially provided with a chocolate coating. In such an arrangement, itis indispensable to arrange a cooling tunnel between the band oven andthe coater, in which tunnel the biscuits are cooled down to atemperature at which they are capable of being coated, i.e., at ca.22-24C. This appears to be necessary due to the fact that the chocolatepaste of the coating would be hurt if the biscuits were delivered at ahigher temperature. Cooling tunnels, associated with such a coater dueto the aforementioned reason, are always required in the pralineindustries where hot or warm stuffings are handled for final products,coated with chocolate or similar temperature-sensitive substances.

For meeting these requirements the provision of a cooling tunnel isknown, the biscuits being advanced through the tunnel on a continuousnet belt made of steel wire. Cold air is blown into apressure chamber,located over the net belt, the air flowing in a vertical directionthrough a perforated plate onto the biscuits or other baked articles. Ithas, however, been found that these and other known cooling tunnelsstill do not entirely fulfill their intended purpose and therequirements set for them. This is especially true when the coolingtunnel is intended to be used selectively in a high-efficiency train inthe form of plates or continuous belts, not only for cooling of singlearticles located separately on the belt, but also for cooling ofstuffings.

It is an object of the invention to provide a cooling tunnel not havingthe above named disadvantages.

it is another object of the invention to provide a cooling tunnel havinga high cooling efficiency but which occupies a limited space and canreadily be set up between two other stations of a working train.

It is a further object of the invention to provide a cooling tunnelwhich solves the condensation problem which is normally a seriousproblem depending upon the type of material being cooled.

it is an additional object of the invention to provide a cooling tunnelin which all parts are easily accessible for cleaning purposes; this isparticularly important when sticky substances are being cooled.

Toward these ends, the invention provides a cooling tunnel with anL-shaped cross section. That part of the conveyor belt receiving thearticles is led through the horizontally arranged longer leg of theL-shaped crosssection. At least one evaporator is incorporated in thevertical shorter leg of the L-shaped cross-section, and at least oneventilator is associated with each evaporator. The empty reverse run ofthe conveyor belt is led back below the longer leg of the L-shapedcross-section outside the tunnel.

A further feature of the invention resides in arranging the ventilatorsand evaporators in the intersection between the two legs of the L-shapedcross-section. Cooling air is directed transverse to the conveyingdirection of the conveyor belt and flows downwardly past the evaporator.The vertical shorter leg has a V-shaped cross-section, and thecondensation drain, formed thereby, is provided with at least one outletfor condensed water.

The advantages obtained with the invention include the fact that thecooling tunnel, which is to be arranged before the coater, may beshorter than is possible with known cooling tunnels. Furthermore,moisture taken up by the cooling air, which passes the material to becooled and condenses at the evaporators, continuously drops down intothe condensed water drain. in addition, the cooling tunnel is easilyaccessible from all sides so that it may be easily cleaned.

One embodiment of the invention is shown in the drawing and will bedescribed more specifically below; the drawing shows a cross-sectionthrough a cooling tunnel.

The cooling tunnel chosen to illustrate the invention has an L-shapedcross-section, the longer leg 1 of the L-shaped cross-section beinghorizontally arranged, and the shorter leg 2 of the L-shapedcross-section extending vertically downwards.

The inner space 3 of the longer leg 1 contains the upper run ofa steelconveyor belt 4, driven in a manner not shown. Conveyor belt 4 is guidedon rollers 5, all of which are rotatably arranged on a single shaft 6,the rollers being axially spaced apart along the shaft. Rollers 5 arepreferably made of stainless steel, having a coating of syntheticmaterial, and run on bearings of synthetic material as a result of whichthey are maintenance free, Shaft 6 rests on supports 7, which extend tohalf the height of the inner space 3. A continuous strand 8 of thematerial to be cooled is shown on the steel conveyor belt 4. This maybe, for example, a strand of a caramel or toffee stuffing, which atincreased temperature is co ntinuously extruded or poured on to thesteel conveyor belt 4 at the entrance of the cooling tunnel. The strandis cooled down to a temperature of 18 22C in the cooling tunnel, so thatimmediately after leaving the cooling tunnel, it may be further handled,e.g., cut into bars which then are fed to a chocolate coater.

The inner space 9 of the shorter leg 2 contains an evaporator 10, whichcooperates with a compressor (not shown) located outside the coolingtunnel, one compressor possibly being associated with severalevaporators 10. Above the evaporator 10 at least one ventilator 12 isprovided in the intersection ll of the two legs 1 and 2, the ventilatorconveying the air in the cooling tunnel downwardly against theevaporator 10, and causing air to flow around the interior of the tunnelas indicated by the arrows.

Between the evaporator/ventilator combination 10/12 and the steelconveyor belt 4 a guide sheet 13 is provided, which together with thesteel conveyor belt 4 in the inner space 3 of the longer leg defines anupper of the shaft 17 is attached to the frame structure 18 of thecooling tunnel and the other end 17b of the shaft is secured to one ofthe support posts 19 for the tunnel.

Hoods 20 and linings 21 of the cooling tunnel are double-walled andprovided with insulating foam filling 22. The hoods 20 can be swungupward towards the middle of the tunnel over a ledge 23, and the linings21 can be lifted out of the frame structure. In each corner of theinterior of the tunnel a rubber ledge 24 may be provided, except onecorner may be used to accommodate electrical cables 25.

The invention has been shown and described in preferred form only, andby way of example, and many variations may be made in the inventionwhich will still be comprised within its spirit. It is understood,therefore, that the invention is not limited to any specific form orembodiment except insofar as such limitations are included in theappended claims.

What is claimed is:

l. A cooling tunnel comprising:

a. an L-shaped housing including a horizontally arranged leg and avertically arranged leg,

b. a continuous conveyor belt having a materialreceiving run locatedwithin said horizontal leg and a reverse run located outside saidhousing, said material-receiving run being arranged to define spacesboth above and below it within said horizontal housing leg,

0. an evaporator located within said vertical leg,

'd. a ventilator arranged to blow air through said evaporator; and

e. means for guiding air from said ventilator through the spaces aboveand beneath said conveyor in a horizontal direction transverse to thedirection of movement of said conveyor.

2. A cooling tunnel as defined in claim 1 wherein said ventilator isarranged at the intersection of said horizontal and vertical legs.

3. A cooling tunnel as defined in claim 1 wherein said ventilator isarranged above said evaporator and directs air downwardly through saidevaporator.

4. A cooling tunnel as defined in claim 1, said guiding means includingmeans between said evaporator and said conveyor belt for guiding airmoving from said evaporator toward said conveyor.

5. A cooling tunnel as defined in claim 1 including guide means dividessaid horizontal leg into upper and lower cooling zones, said guide meansbeing spaced from the end of said horizontal leg remote from saidvertical leg to define a communication path for air flowing from one ofsaid zones to the other.

6. A cooling tunnel as defined in claim 1 wherein the lower end of saidvertical leg is provided with means for collecting condensation, and anoutlet for removing the condensation collected.

7. A cooling tunnel as defined in claim 6 wherein said collecting meansincludes the lower end of said vertical leg being formed with a V-shapedcross-section.

1. A cooling tunnel comprising: a. an L-shaped housing including ahorizontally arranged leg and a vertically arranged leg, b. a continuousconveyor belt having a material-receiving run located within saidhorizontal leg and a reverse run located outside said housing, saidmaterial-receiving run being arranged to define spaces both above andbelow it within said horizontal housing leg, c. an evaporator locatedwithin said vertical leg, d. a ventilator arranged to blow air throughsaid evaporator; and e. means for guiding air from said ventilatorthrough the spaces above and beneath said conveyor in a horizontaldirection transverse to the direction of movement of said conveyor.
 2. Acooling tunnel as defined in claim 1 wherein said ventilator is arrangedat the intersection of said horizontal and vertical legs.
 3. A coolingtunnel as defined in claim 1 wherein said ventilator is arranged abovesaid evaporator and directs air downwardly through said evaporator.
 4. Acooling tunnel as defined in claim 1, said guiding means including meansbetween said evaporator and said conveyor belt for guiding air movingfrom said evaporator toward said conveyor.
 5. A cooling tunnel asdefined in claim 1 including guide means divides said horizontal leginto upper and lower cooling zones, said guide means being spaced fromthe end of said horizontal leg remote from said vertical leg to define acommunication path for air flowing from one of said zones to the other.6. A cooling tunnel as defined in claim 1 wherein the lower end of saidvertical leg is provided with means for collecting condensation, and anoutlet for removing the condensation collected.
 7. A cooling tunnel asdefined in claim 6 wherein said collecting means includes the lower endof said vertical leg being formed with a V-shaped cross-section.